The northward migration of grizzlies has led to more sightings of “grolar” bears in the Arctic.

The northward migration of grizzlies has led to more sightings of “grolar” bears in the Arctic.

Hunters from the village of Ulukhaktok, N.W.T., knew there was something different about the polar bear they were stalking but couldn’t put their finger on it.

It was far more aggressive than anything they were used to. They even called off the dog for fear the large white mammal would kill it.

On closer inspection after it was shot and killed, it turned out not to be an ordinary polar bear but one that was a cross between a polar bear and a grizzly, unofficially known as a “grolar bear” and “pizzly.”

“The first hybrid we had ever seen around here a few years ago was pretty nasty. They (hunters) usually stalk the polar bear using a dog, but this bear was so aggressive they couldn’t use a dog on them. It was too dangerous,” Robert Kuptana, who lives in the western Arctic hamlet of about 400 people on Victoria Island, told the Toronto Star Friday.

Over the years, as grizzly bears wandered further north following the caribou herd, the hybrid variety became more common, said the 69-year-old Kuptana. He added that a hunter from the village, Pat Ekpakohak, and his two grandchildren killed three of them just 10 days ago.

“One is pure white, one is partly dark and the other is fairly dark brown and the top part is white,” said Kuptana, who took a picture of the skins.

Polar bear and grizzly habitats overlap in the western Canadian Arctic around the Beaufort Sea. Grizzlies are known to occasionally to go out on the ice in the spring to feed on seals killed by polar bears, according to the Canadian Wildlife Service.

A DNA test conducted by the Wildlife Genetics International in British Columbia on a bear shot and killed by an American hunter in 2006 confirmed it was a hybrid, making it the first documented case in the wild.

Ian Stirling, a research scientist and polar bear expert with the Canadian Wildlife Service in Edmonton, said in an interview with National Geographic that the hybrid was “definitely not” a sign of climate change.

Andrew Derocher, a professor of biological sciences at the University of Alberta, is in Ulukhaktok, where he is doing polar bear research and saw the skins from the three hybrids.

“It seems to me they are getting a lot more common, at least in this part of the Arctic,” he told the Star.

“I think the story here . . . is that the number of grizzly bears on Victoria Island has increased quite markedly over the last 20 years. And part of that might be related to changing environmental conditions up here. It’s a bit warmer and it’s quite clear the grizzly bears are well-established here now and, of course, there is a healthy population of polar bears around,” he said.

David Paetkau, president of Wildlife Genetics International, based in Nelson. B.C., told the Star it was a “quirky” development that can’t be totally explained.